Evaporative wheel



March 31, 1959 W E 2,879,979

EVAPORATIVE WHEEL 3 Sheets-Sheet 1 Filed Nov. 8, 1956 INVENTOR Byr/r/ E W/IEEL ER ATTORNEYS March 31, 1959 BFIWHEELER 2,879,979 I EVARORATIVE WHEEL Filed Nov. 8, 1956 5 Sheets-Shet 2 men Byr/z/ 1-? WHEELER March 31, 1959 B. F. WHEELER v INVHVTOR Byr/I/ 5 WHEELER limited States Patent 2,879,979 Eva-Panama WHEEL liy'rhl F. Wheeler, Montreal, Quebec, Canada Application November 8, 1956, Serial No. 621,086 1 claim. c1. zen-92 I The resent inventioh relates to liunridif ing apparatus, and more particularly to an improved evap'ol'ative wheel adapted to be used in such humiditying a paratus. v

Evaporative wheels or fluid treating wheels, which errib'od'y spirally wound sheets or strips forming a drum or rotor used for contacting a liquid with a gas or other fluids, are known. 7 i

In knowh wheel constructions, the spirally wound strips have to be maintained together as a rigid unit by means or ushap'ed holding elements, surrou din the wheel, and attached to the core of the when. Said holdii'rig element's form obstructio'ns to the free passage of the air through the wheel, and cause undue vibration "ahtlnoi'se during operation of the humidifier.

msreaver, in known humidifiers or the eharaeter describ d, in which an eva oiative Wheel is partially immersed in a "water eentaihin tank orteservo'ir, it frefqiier'itly happens that when the water level within 'the reset-van is reiafivei 16w, and onl part or the wheel is wett'ed by the water, the central part of the wheel faunas dry and is inoperative, thereby considerably reducing the evapmanve eflicie'ncy er the humidifier apparatusasawhole. V I

Another serious problem arising in known humidifier constructions, i the fact that, the apor'ativ'e wheel is normally rhade of sheet meta-1 which becomes rusty 'or corroded with use, and difficult to clean, resulting in 'an iinsar'iit'ary conditioh. When the sheets for making the evaporative wheel are made ofmetaLfth'ere is the probkm of expansion andcontraotioh of the metal sheets iiueit'b the fact that said sheets have lengths :of as much as lOi) feet. 'lheexpansion andcontra'ction effectscrea'te a'serioiis problem rendering the eva drative wheel noisy 'ven aftera s'hor 'fipe'riodof u'se. Accor'tling'ly,'the general object-of the present invention is the provision of an improved evaporauve whee'L/for use in humidifiers, which is so constructed "as to obviate the'ab ov'e 'rioted' disadv garages.

"Ah 'irnportant object "of the prefseiitinvention i the provision ofan'eyaporativewh'el in which, oneo'f two spirally wound strips of sheet material is provided 'with projections extending radially outwardly from both 'faces ofeaid use sheet, 'and"soform'ed, as toptovide an outside cdiitactsurfade'ofsubstantial area, adapted to'contact the other sheet and be secured thereto, to "thereby erm a ri'giiiwheel unit "without the requirement of U sha ped holding "elements or other fastening means, thereby eliminating obstructionstothe air passage through the wheel andconsequently noisy operation. Thusthe projections serve as fastening means, as well asfisp'acer members fo'r'the convolutionsof the strips.

' Still another important object of the present invention is, the provision of an evaporative wheel of "the character described,injwhich the convolutio'ris of the'sh'eet material are'm'ade of a synthetic 'plastic materiaL'prefra'bly polyethylene, which is easily cleaned and maintained in 3a sanitary -cohdition**an'd which does away with the lprobkm of expansion and contraction.

2,879,979 Patented Mar. 31, 1959 Still another important object of the present invention is, the provision of an evaporative wheel of the char= aeter described in which, the projections mentioned above have such a shape as to retain a reserve of liquid therein, which is allowed to flow down the surface of the wheel convolutions, and reach the inner layers of the wheel, so as to wet the entire operative surface of the wheel, even when the level in the reservoir is relatively low and only the outer marginal portion of the wheel is immersed therein.

The foregoing and other important objects of the present invention, will become more apparent during "the following disclosure and by referring to the drawings which: i I Figure l is a perspective view of the evaporative wheel;

Figure 2 is an end elevation of the same showing part thereof on an enlarged scale;

Figure 3 is a longitudinal section of a humidifier in which an evaporative wheel according to the present invention is used;

Figure 4 is a partial perspective view of a strip of "sheet material provided with struck-out projections;

Figure 5 is a perspective view of the core of the wheel, on which the strips of sheet material are partially wound;

Figure 6 is a diagrammatic partial end elevation of the central part of the convolutions of the wheel;

Figure 7 is a partial diagrammatic end elevation of the peripheral portion of the wheel, in the part thereof where the projections separating the spirally wound sheets start to dec're'asein height;

Figures '8, 9 and 1'0 are similar end elevations of the successive parts of the wheel adjacent and following the part shown in Figure 7;

Figure 11 'is a partial end elevation of the middle .part of the wheel, showing how the water is retained by the projections when that part of the wheel moves upwardly from'the water reservoir;

7 Figure 12 is a similar partial elevation taken when that part of the wheel moves horizontally at the top of the'wh'eel;

Figure 13 is a similar elevation taken when that ,part of the wheel 'is moving downwardly towards the water reservoir; and

Figures 14 to '19 inclusive illustrate, in a diagrammatic manner, how the water taken up by the peripheral part 'of'thefwheel, gradually moves towards the center or core part of the wheel, and "finally wets the entire operative surface of the same.

1 Referring now more particularly to the drawings, in which like reference characters indicate like elements throughout, the evaporative wheel according'to thepres- 'erit invention, which is-shown-atl in'Figure Lisadapted to be used in conjunction 'with a humidifier unit, the essential components of which are shown in vFigure 3. Said humidifier unit comprises a reservoir 2 .for eontaining water 3, in which is partially immersed the evaporative 'wheel 1, provided with a shaft 4, journalled =on a bracket 5 atthefront end of the'humidifier and =.term'ihating short of the rear face of the wheel 1 as-shown at 6. Theevaporative wheel 1 is rotated atra slow-speed, by'means of an electric motor 7 and speed -.reducing unit 8, which drives a supporting wheelfi engaging a cup shaped member 10, forming-part ofthe core-of evaporative wheel '1. Air 'is passed through :the .upper portion of the wheel, by means of a fan 11 driven by an electric motor '12. The "air whichipasses throug'h the spaced convolutions of the wheel -1, comes in 6011133811 with the wetted surfaceof said convolutions,aan'dtevapo rates at least part of the water and is humidifiedtth'ereby.

The core of the evaporative 'vvheel 1 c'onsists of the shaft 4; previously described, on whioh are lnounted 'tWo spaced cup shaped members of circular contour, provided with an annular flange 14, and so mounted that, the recess of each cup shaped member faces outwardly of the wheel, as shown in Figures 3 and 5. The shaft 4 projects from one cup shaped member at one end thereof, and terminates at the other cup shaped member at its other end.

The evaporative part of the wheel, is constituted by at least two strips 16 and 17 of sheet material, wound around the core, so as to form a plurality of spaced spiral convolutions. Said strips 16 and 17 are preferably made of a synthetic resin sheet material such as polyethylene. The strip 16 has a smooth surface on both faces thereof, and is without any holes or projections, while the strip 17 is provided, at spaced areas along its length and Width, with struck out projections 18 which extend radially outwardly from the opposite faces of said strip, as clearly shown in Figure 4. Each projection 18 has a dome shape of substantially trapezoidal cross-section, and consists of two inclined and converging straight portions 19, integral with the main body of the sheet, and joined at their upper end by means of a transverse substantially fiat portion 20. The projections 18, therefore, consist of a strip portion integral with the strip 17 at both ends, and cut out from said strip 17 along the longitudinal edges thereof. The projections 18 are preferably made by a pair of oppositely moving adjacent dies, working from opposite faces of the sheet material, so as to form oppositely extending projections which are adjacent to each other, as clearly shown in Figure 4.

The outside surface of the substantially fiat portion 20, has an area large enough to make good contact with the face of the smooth and continuous strip 16, as clearly shown in Figure 6, such that said outside surface of the portion 20 may be secured or fastened to the strip 16, by means of a glue or adhesive. But in the preferred method of constructing the wheel according to the present invention, and when the strips 16 and 17 are made of polyethylene, said strips are sprayed with a polyethylene solvent as they are wound on the core of the evaporative wheel, whereby the top surface layers of the strips 16 and the outer surface of the portions 20 of the projections 18 become sticky, and will adhere to each other and be cemented together.

According to still another method of securing the various convolutions of the strips 16 and 17, the latter are first wound on the core of the wheel and then the polyethylene solvent is sprayed through the wheel, that is, between the spaced convolutions of the strips, whereby the solvent penetrates between the outer surface of the portion 20 of the projections 18 and the contacting surfaces of the strip 16, and partly dissolves the surface layers of said contacting surfaces and renders them sticky, whereby fastening of the same is effected. According to either one of the above described methods, once the surfaces of the strips 16 and 17 are dried, the various convolutions of said strips are fastened together to make a rigid wheel unit, without the necessity of using additional fastening means.

Due to the fact that the projections 18 extend from both faces of the strip 17, said strip 17 will be equally spaced from the two adjacent strips 16, as clearly shown in Figure 6 or Figures 11, 12 and 13.

In order to construct the wheel so that it will be perfectly cylindrical, and also statically as well as dynamically balanced, so as to obtain smooth rotation thereof despite the spiral winding of the strips 16 and 17, the central part of the wheel, that is the part next to the cupshaped members 10 forming the core of the wheel, is constructed and assembled as shown in Figure 6, while the peripheral or outer end parts of the strips 16 and 17 are assembled and constructed as shown in Figures 7 to 10 inclusive.

Referring to Figure 6, it will be seen that the inner end of the strip 16, which is immediately wound on the cup members 10, projects beyond the inner end of the strip 17, and that this strip 17 is provided with a radially inwardly extending projection 18, of smaller height than the projections 18 of normal size. Successively, there are provided gradually increasing inwardly extending projections 18', until, after one full turn, a projection 18 of normal size is formed. Similarly, there is a first radially outwardly extending projection 18, and thereafter there are similar outer projections of gradually increasing size until, after substantially a full turn, the projections are of normal size on both sides of the strip 17.

In the few last windings of the strip 17 of the periphery of the wheel 1, the radially inwardly extending projections 18 first start to decrease in height, until the strip 17 comes in contact with the radially inwardly adjacent portion of the strip 16, as shown in Figure 7. Then the radially outwardly extending projections 18 start to decrease in height, as shown in Figure 8, until the same portion of the strip 17 comes in contact with the radially outwardly adjacent portion of the strip 16, as shown in Figure 8. Finally, as shown in Figure 10, both strips 16 and 17 are now in direct contact with each other, and to increase the rigidity of the outer layer, the strip 17 is wound for a few turns and fastened as shown in Figure 10.

The shape of the projections 18, apart from providing good contact surfaces with the strips 16, in order to properly fasten the convolutions of the strips 16 and 17 together to form a rigid wheel unit, also provide dihedral angles, as clearly seen in Figure 11, which pick up water from the reservoir 2, said water remaining in said dihedral angles, as shown at 25 and 26 in Figure 11, while the wheel is travelling upwardly from the water reservoir. When the same portion of the wheel travels substantially horizontally, as shown in Figure 12, the water starts to flow down along the strips 16 and 17, and further adds water to the already wetted surfaces of said strips. Due to this and also to the fact that the sheets are spirally wound, it is possible to obtain a completely wetted surface of the wheel, even if the water level within the reservoir 2 is relatively low, and only the peripheral layers of the strips of the wheel are immersed in said reservoir.

Referring to Figures 14 to 19, it is clearly shown that when the evaporative wheel 1 rotates in the direction of the arrow 30, and that only the outer peripheral layer of the wheel is immersed in the water 3 of the reservoir 2, the water lifted by the wheel and collected in the projections 18, will gradually flow down to the inner layers of the strips, as indicated by the arrows 31 in Figures 15 to 19 inclusive, until all of the operative surface of the wheel is wetted.

While a preferred embodiment according to the present invention has been illustrated and described, it is understood that various modifications may be resorted to without departing from the spirit and scope of the appended claim.

I claim:

An evaporative wheel for a humidifying apparatus comprising a rotor core, two strips of sheet material made of a synthetic resin longitudinally wound in substantially parallel arrangement on said core to form spiral convolutions about the core, one of said strips having smooth opposite surfaces without any projections thereon, the other of said strips having, at longitudinally and transversely spaced areas thereof, pairs of adjacent projections struck out from said strip, the adjacent projections of each pair extending outwardly of and from the opposite faces of said strip, each projection having a. dome shape and constituted by two inclined and converging parts forming a dihedral angle with the strip, and an intermediate part connecting the adjacent ends of said converging parts, the other ends of said converging parts being integrally connected to said strip along lines extending transversely of said strip and spaced from each other longitudinally of said strip, said intermediate References Cited in the file of this patent UNITED STATES PATENTS Slagel -2- July 26, Robic Mar. 28, Robic Nov. 26, Nicol Oct. 7, Dixon Oct. 28, Piccard Apr. 20,

FOREIGN PATENTS Netherlands Oct. 15, 

